Illuminated sign



Oct. 12, 1937. F. J. OBERACKER 2,095,558

ILLUMINATED 5 IGN Filed Jan. 2 1936 Patented Oct. 12, 1937 UNITED STATES PATENT OFFICE 6 Claims.

This invention relates to an illuminated sign of the type consisting essentially of a plate of transparent material such as glass having characters, figures or-the like intagliated in one or both faces thereof, light being projected into the sheet through one or more edges thereof in rays which are parallel or nearly parallel to the faces of the plate so'as to strike against the sunken surfaces which form the design and to 10 illuminate the same, the light rays being totally reflected within the plate from the plane portions of the faces.

It is an object of the present invention to provide a sign of this type which is suitable for out-door use. Edge-illuminated signs as heretofore constructed are subject to the objection that any dust, scratches, finger marks, drops of water, or other substance on the surface of the illuminated glass plate will permit the escape of 20 light through the surface at such points so that the effectiveness of the sign is greatly reduced.

According to the present invention, the illuminated plate is protected by a transparent sheet of glass or other suitable material located in front 2 of the illuminated plate and spaced therefrom. The edges of this protective sheet are masked so as to prevent the entrance of light rays into the protective sheet through the edges thereof. Thus there are no totally reflected light rays within the sheet to be caught and projected out ,by the dust, raindrops and the like. In order to produce contrasting color effects, the sunken surfaces forming the design in the glass plate may be coated with enamel or other coloring matter 35 of any desired shade. To contrast with the colored figures thus produced, a backing member of any contrasting color may be mounted behind the intagliated plate. This member may be opaque if desired.

Another object of the invention is to provide an improved housing to contain an assembled unit consisting of an intagliated transparent plate, a protective sheet in front, and a backing member, the housing also being adapted to contain one or more sources of light adjacent to edges of the intagliated plate.

For a more complete understanding of the invention, reference may be had to the description thereof which follows and to the drawing of which Figure 1 is a perspective view of an illuminated sign embodying the invention,vone of the end pieces of the housing being removed.

Figure 2 is a perspective view of an end piece 55 of the housing.

Figure 3 is a section on the line 3-3 of Figure Figure 4 is a section on the line 4--4 of Figure 1.

Figure 5 is a fragmentary perspective view of the various elements which may be used to make a removable unit for the housing shown in Figure 1.

Figure 6 is a fragmentary perspective view of such a unit."

Figure '7 is an elevation of the complete sign, a portion being broken away.

The sign illustrated in Figure 1 includes a suitable housing consisting of an elongated housing member l0 having a rear wall 12, a top wall l4 with a front flange l6, and a bottom wall l8 with a front flange 20. On the top wall l4 near the ends thereof are permanently secured a pair of channel members 22 and 24 each of these members having a front flange 26 and a rear flange 28 spaced from the upper flange l6 and the rear wall l2 of the housing member In. Secured to the bottom wall l8 are similar channel members 30 and 32, each of these members having a front flange 34 and a rear flange 36 spaced respectively from the lower flange 20 and the rear wall l2 of the housing member Ill. In order to enclose the ends of the housing, end members 40 and 42 are provided, these members being identical in structure if desired. As shown, each end member comprises a rear wall 44, an end wall 46 and a front wall 48, the rear wall 44 having a forwardly projecting lug 50 thereon which is adapted to spring into a perforation or recess 52 in the rear wall I2 of the housing member In so as to lock the end member 40 in position. When the end member 40 is pushed into position, the upper and lower margins of the rear wall 44 ride in. the clearances between the flanges 28 and 36 and the rear wall l2 of the housing member III. The upper and lower margins of the front wall 48 of the end member ride in the clearances between the flanges 26 and 34 and the flanges l6 and 20 respectively:

Within the housing thus formed are mounted a sign unit and one or more sources of light. As shown, the sign unit consists essentially of a thick plate 60 of transparent material such as clear glass. In one or both faces of this plate the desired design is formed in intaglio. The design may consist of letters, figures or any other characters as desired, such design being formed by removing portions of one or both of the plane surfaces of the plate so that the design is formed by sunken areas, preferably in the rear face of the plate, as indicated for example at 62 in Figure 4. If color effects are desired, the sunken areas may be covered by paint, enamel, stain or any other suitable coloring matter. Behind the intagliated plate 60 a backing plate 66 may be mounted, this plate preferably having a color contrasting-with the color or colors of the design. As shown, the backing plate 66 is of thin material such as sheet metal, the upper and lower marginal portions being bent around the upper and lower edges of the plate 60 so as to form upper and lower flanges 68 and I0 engaging the front face of the plate 60. If desired, the backing plate 66 may be slightly spaced from the rear face of the plate 60 as by strips 12 of cardboard or other suitable material resting against the marginal portions of the rear face of the plate 60. In front of the plate 60 is a protective sheet of trans parent material such as glass or the like. This sheet is preferably spaced from the front face of the plate 60. To this end, the upper and lower marginal portions of the sheet 80 may rest against the flanges 68 and 10, these flanges serving as spacing elements between the plate 60 and the protective sheet 80. Additional spacing elements 82 may be employed between the plate 60 and the protective sheet 80 at the ends thereof. As shown, the spacing elements 82 may be in the form of channels fitting over the end edges of the sheet 80 so that these elements not only serve as spacing elements but also mask the end edges of the sheet 80 to prevent entrance of light rays into the sheet therethrough. It is preferred that the portions 83 of the channel elements 82, which lie between the plate 60 and the sheet 80 and which thus serve as spacers, extend from the end edges of the unit far enough to intercept any light rays which might emerge from the plate 60 by refraction. It is desirable to seal the spaces between the plate 60, the backing member 66 and the protective sheet .80 against moisture, dust and the like. To this end, as indicated in Figures 5 and 6, the spacing elements 82 may be cemented to the end edges of the sheet 80 as at 8|. The end edges of the backing plate 66 and the spacer I2 may also be cemented as 86, the cement being carried around the bent edges of the backing plate until it meets the line of cement 84 at the upper and lower ends of the spacing element 82. The upper and lower margins of the sheet 80 are also cemented against the front faces of the flanges 68 and I0 of the backing plate. This results in a sealed unit in which the faces of the plate 60 are protected from moisture, dust and the like, but its end edges are exposed. This unit may be mounted within the housing member I0 so that the upper and lower margins of the protective sheet 80 are pressed against the flanges I6 and 20 by suitable spacing members and 92 within the housing. This provides a hollow space 84 back of the sign unit for electric wiring, In the end portions of the housing space is allowed for suitable sources of light such as small electric lamps. Figure 1 shows a conventional electric lamp I00 mounted in a suitable socket I02 which is secured in the housing in such position that the lamp I00 will be directly opposite an end edge of the plate 60 so that light from the lamp will shine into the plate 60 through the adjacent edge thereof. As indicated in Figure 1, a lamp is provided at each end of the sign unit so that the figures on other elements of the design will be illuminated from both sides. The rays from the lamps I 00 which enter the plate 60 through the end edges will for the most part be totally reflected within the plate since they meet the plane faces of the plate from within at a smaller angle than the critical angle. Near the ends of the plate. however, some of the light rays may meet the faces of the plate at angles greater than the critical angle, in which case such rays would pass through the face of the plate. The portions 83 of the channel elements 82, however, are preferably of sufllcient width to intercept such rays and thus to prevent stray illumination at the end portions of the sign.

The lamps I00 are connected by suitable wiring in a manner well known in the art, the lead-in wire I06 preferably having a grommet I08 thereon within thehousing, the grommet being pinched against the insulating cover of the wire so as to take up any mechanical pull which may be imposed upon the lead-in wire I06 and thus to protect the interior connections. Each lamp socket I02 may be mounted on a suitable carrier III which in turn is secured to the housing I0. If desired, the holder I I0 may be removable so as to permit the removal and replacement of the sign unit between the lamps. The end members 40 and 42 may be readily removed at any time by springing their rear walls sufficiently to withdraw the lugs 50 from the perforations 62. Thus the lamps I00 are readily accessible for replacement.

Various changes and modifications may be made in the structure herein shown and described without departing from the spirit or scope of the invention as defined by the following claims.

I claim:-

1. A sign unit for edgewise illumination, consisting of a rectangular plate of transparent material having a design intagliated on a face thereof, a plate of opaque material adjacent to a face of said transparent plate and slightly spaced therefrom, a protective sheet of transparent material adjacent to the other face of said transparent plate and slightly spaced therefrom, a marginal waterproof seal between said plates and protective sheet, and opaque means masking all the edges of the protective sheet and the top and bottom edges only of said transparent plate, the end edges of said transparent plate being left exposed for the admission of light to illuminate the unit.

2. A sign unit for edgewise illumination, comprising a rectangular plate of transparent material having a design intagliated in a face thereof, an opaque plate adjacent to but spaced from one face of said transparent plate, a transparent protective sheet adjacent to but spaced from the other face of said transparent plae, and means at the margins of said unit permanently sealing the spaces between said plates and protective sheet and masking the edges of the unit except for the end edges of the transparent plate which are left exposed for the admission of light, said means including a channel member fitted over each end edge of said protective sheet and cemented to the adjacent face of said transparent plate.

3. A sign unit for edgewise illumination, comprising a plate of transparent material having characters intagliated in a face thereof and having its end edges exposed for the reception of light, a sheet metal member behind said intagliated plate, said metal sheet having a pair of flanges bent over the upper and lower edges of the intagliated plate to rest against the upper and lower margins of the front face thereof, a protective sheet of transparent material in front of said intagliated plate engaging said flanges and spaced from said plate thereby, means masking the end edges of said protective sheet, and means preventing access of moisture to the spaces between the plate and sheets.

4. A sign comprising a, channel-shaped housing member having an Open front and open ends, a removable unit in said open front spaced from the rear wall of said housing member, a source of light at each end of said unit adjacent to the end edges thereof, and end members removably attached to said housing member to enclose said light sources and the ends of said unit, said unit including a plate of transparent material havin characters intagliated in a face thereof, a protective sheet of transparent material infront of said intagliated plate and spaced therefrom, an opaque sheet behind said intagliated plate, and means for masking the end edges of said protective sheet to prevent entry of light therethrough.

5. A sign comprising a housing member having a rear wall with perforations therein, top and bottom walls and upper and lower front flanges on said top and bottom walls respectively, end members each having a rear wall adapted to engage against the rear wall of said housing member and provided with a lug for locking engagement in one of said perforations, an end wall to form an end of the housing, and a front wall to engage portions of said flanges, channel elements permanently secured to the top and bottom walls of said housing member near the ends thereof to overlap the front and rear walls of said end members, a plate of transparent material mounted within said housing member and having an intaglio design in a, face thereof, and a light source mounted adjacent to an edge of said plate.

6. A sign unit for edgewise illumination, comprising a plate glass plate having characters in tagliated in a. face thereof and having its end edges exposed for the reception of light rays, thin marginal spacing elements against the rear face of said plate, an opaque sheet behind said plate and spaced therefrom by said elements, said opaque sheet having top andbottom flanges extending past the upper and lower edges of the plate and engaging the upper and lower margins of the front face thereof, a pair of channel elements cemented to the end margins of the front face of said plate, a protective glass sheet having its end margins cemented into said channel elements and its upper and lower margins cemented to said flanges, whereby said protective sheet is spaced from said plate by said channel elements and said flanges, and watertight cementitious material sealing the spaces between said plate and said sheets.

FREDERICK J. OBERACKER. 

